Piper Super Cub MicroMold Balsa Kit A-CK8 for C02 Power

Started by sunk?, August 29, 2011, 06:38:46 PM

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sunk?

hi guys,
"You take a lot of pain and meticulous effort "vc
  It  May be because I did so much scale work, some thing like a 'profile build' seems a little   '1/2 way' ??
but I think this is the way I must go ...even if it is just to keep the price down :) :) :)
not sure what size a 0.49 is ....comparable to the power of the old 3000 'CO' motors? [ compressed air]
regards
don
regards
don
UK

sundaram

Cox 0.049 Glow is a powerfull little beast, just about say around 100gms incl all accessories. Nitro Hungry, drives a 6x4 prop comfortably. Ideal is 5x5. Can fly a light balsa model of wing span up to 39 Inches. Could see the photo of cox 0.049 on the cowl of the model on the ebay link provided so the querry.

Not really come across a CO engine, so cannot comment really.

sunk?

hi mate.
that sounds good then.
mine came out at a mean 10 onz or 280grams with 2c lipo, esc and rx
not much room in the fuse
motor mount [ nose without cowl] to trailing edge of wing...... 14cm
hight of fuse 'box'........ 3cm
width of fuse 'box' ...... 4cm
not room for  a very big tank under wing
regards
don
regards
don
UK

sunk?

hi guys.
just an update.........
I had tech difficulties with the motor I was going to use......... built in prop saver, but one screw was not a good thread fit and gave out when swaoping to another prop. so I had to change the motor to to the 'blue' 1700kv.. now swinging a 8 x 5 prop cut back to 7 x 5........not enough ground clearance for the 8...It was within mm of the floor when tail was flying.........
so any way a quick video for you .....holding down by the axle and varying degrees of throttle applied......


the elev still not on servo......still waiting but now have the rods done and horns fitted.
you comments .........

next job while waiting for the servos I will fit a short ground/base loaded aerial to get rid of the long MHz aerial seen wrapped around the fuselage at the moment.
and may be longer under carriage strutts :) :)
regards
don
regards
don
UK

sunk?

hi guys,
just to illustrate how I use servo horns on control surface.
front of control horn....


rear of control surface to show the 'stub' of the servo center which stops the arm going right through the control surface.


regards
don
regards
don
UK

ashJR7202

Hi Don, amazing build!!!
with perfection!!!!! and detailing!!!!

just a small doubt....are u using 24gm blue wonder motor? i think it will be little heavy and overpowered... just doubt!!

i think 16gm HXT motor from HK will be best for ur plane!!! with 300-500 mAh 2s Lipo, 15A ESC and suitable prop with 5gm or 4 gm servos!!!!!

all the best for ur built

Ashish
Hanger: Mini Yak-54| 210 Phantom | SU-47| F-15| EuroFighter|Scrappy|SU 27|Eurofighter|Sukhoi PAK FA
Blade MCX| Blade CP PRO
JR XP7202| DX7

sunk?

hi mate.
I am not very well up on motors so just looked for one that had 300+thrust with what ever prop they suggested at 2s volts ......most seem to like 8in + sizes :)
so I have had to redesign the under-carriage to give ground clearance.......... perhaps 'functional' and not aesthetic /scale type looks is the way to go :) :)
new undercarriage and prop cut down from 8in to 7in

gear now wider footprint and taller.

STILL waiting for arrival of servos............

regards
don
regards
don
UK

rcpilotacro

Don, is this a slow fly prop? Will it suit? , prop tips are sawed off or what? Is it balanced ? Apparently not(I reiterate apparently), recheck your horn again, the hole in the horn should be in line with the hinge, perfection at this will be better. Why prop saver on a balsa model, models with slightly higher pull, prop saver won't work. Just my 2c bit.
Gusty's Hangar and Introduction.

A Good pilot will practice until he gets it right,
A Great pilot will practice until he can't get it wrong.

rcpilotacro

#33
1. I read that 8x5 to 7x5. Not a good idea, the helical twist of a prop needs to taper to near zero at the tips, other wise(a) there will he tip loss and (b)might vibrate as well, consider changing the prop
2. Is the wing laterally balanced? stbd balsa seems to have a nudge, that could cause lateral static imbalance, unlike foamie, balsa model making is real aeromodelling, and you have done a fantastic job  :hatsoff: (Sorry my foamie friends)
Gusty's Hangar and Introduction.

A Good pilot will practice until he gets it right,
A Great pilot will practice until he can't get it wrong.

sunk?

hi mate,
the prop savers came with the motor.....to be honest with the size of the rubber supplied I doubt it would work ...I take it the idea of a prop saver is for the rubber to give out at contact?........... these rubbers are 'big' hahaha,
I got a spare set and they are more like elastic bands than this one is.
the prop is ballanced staticly and does not vibrate at all any where in the rev range.as for the tip off...............this I read some where but may have been ..just to get back in the air quickly...with the larger landing gear I can just get away with an 8in but not sure if as you said earlier it may not need that big a prop,
I tried vertical running and there is  not quite enough power to hold it vertical, makes it very light and 'floaty' with my hand around the fuselage...
how would you test for prop size ? purly in flight?
idealy I think it prob does not want the motor to run at full revs once airbourne?
my knowledge of plane flying is sadly lacking I'm afraid.
wings.......they are laterally balanced, but the construction is such..........just a sheet of basla with formers added :) ........... that there could well be 'inbuilt probs'  not having a proper frame work ...trouble with the early cheap kits........... they look even and when on the craft it is laterally balanced as well . but I suppose airflow is the big test. :)
the next kit will be a proper one with frames and spars...hopefully this may be a reasonable trainer......I have a few years on helis but planes were 30+ years ago now.;)
horns.....this may be why 'in the post on horns etc......... no body used servo horns in this way I will see if they will angle enough to be at the hinge,....or even buy some hahaha.
what do you find is good hinge? I tried the flexy plastic but adhesion is not what I would have liked.
.........thinking of wire rods..........
regards
don
regards
don
UK

rcpilotacro

Floaty is good, Just give it a good run before lift off, I still suspect your Thrust line(Both the Firewall, and the mount), Rudder horn above the wing? wont it be better if it went under with the servo arm facing downwards to give you a good clean sweep of the servo and throw o fthe rudder. Front wing dowel is interesting. mmm . a control rod sweep at an angle will change your throw at sine of the servo to horn sweep angle. no?. May be i am nitpicking, She is good to go stock. :thumbsup:
Gusty's Hangar and Introduction.

A Good pilot will practice until he gets it right,
A Great pilot will practice until he can't get it wrong.

sunk?

hi mate.
thanks for your comments. maiden will tell eh?
still waiting for the 4g servos :)

regards
don
regards
don
UK

sunk?

hi mate.
front wing dowel?
position questionable?
the position is low as there was supposed to be a plexi cabin,
but I filed it in as there was not enough room for the electrics.......:)
regards
don
regards
don
UK

rcpilotacro

Practically seen, rubber pulled down more tends to lift in flight, don't ask me why, I dunno, observed data. That's why dowels are closer to the wings. For a small aeroplane may not matter
Gusty's Hangar and Introduction.

A Good pilot will practice until he gets it right,
A Great pilot will practice until he can't get it wrong.

sunk?

hi mate.
yes I see the potential prob.
more elastic may not be so tight so still gives movement.
when I pickup by the wings it is quite hard to pull separate.
regards
don
regards
don
UK

sunk?

hi guys,
well the servos have actualy arrived now and fitted with reversing and throws sorted.
the rudder fin is now mounted with a rod hinge as the flex plastic adhesion was definitely not good, the elev seems ok with flex plastic hinge though.
also I have covered the under side of wing..............
1/   because I thought it did not look right ;)
2/   because of the spar giving the dihedral was exposed and I have a feeling I read somewhere an exposed spar under the wing surface slows the plane down........
also I have fitted the soft plastic cowling at the front with air flow vents.


the problem now is autum is here and we are in quite strong winds     [for this size plane :) ]  15 -20 mph
so maiden will be in a while.

regards
don
regards
don
UK

rcpilotacro

Gusty's Hangar and Introduction.

A Good pilot will practice until he gets it right,
A Great pilot will practice until he can't get it wrong.

sunk?

hi mate.
It was not until I took that pic I saw the 'blow out' on the new under wing skin at left wing leading edge.......this is now rectified :)
that would most likely have given an 'auto left turn' being blunter than the right wing leading edge :) :) :)
and I will prob need all the help from the air frame I can get :) :) :)
also I have put the lighter prop save rubber on...........
would it pay me to get the threaded nose cone assembly for the prop then do you think?
regards
don
regards
don
UK